The Distance Between Yesterday and Tomorrow
by lovablegeek
Summary: S1 - Sometimes Jack can avoid his past, and sometimes parts of it land on his doorstep in exactly the wrong combination. Jack/Rose - Complete
1. Intersect

The only reason for time is so that everything doesn't happen at once.  
- Albert Einstein

"_So_," Rose said, eyes on the central column of the TARDIS as the piston slowed to a stop. "Where are we, then?"

Jack grinned and bounded over to one of the console screens, tilting it up towards him to study it for a moment. "Well... according to this, we should be just about-"

"When did you learn to read that?" the Doctor asked with a frown, straightening from where he'd leaned over the console. Jack chuckled and stepped back from the console again, hands raised in surrender.

"I didn't, actually. I just counted on you interrupting me right there anyway - might as well sound like I know what I'm doing in the meantime."

The Doctor reached over to cuff him lightly on the side of the head, though he smiled as he did, and Rose laughed, which was exactly what Jack was going for in the first place.

"You're impossible, do you know that? One of these days, I'm just going to stop listening to you."

Reaching out with one hand, Jack caught Rose around the waist and pulled her to him, prompting a startled giggle from her. "Well, until then..."

"Until then," Rose said, twisting around in his arms to face the console, "I _still_ want to know where we are."

"Cardiff," the Doctor announced, flipping a switch or two on the console without looking up. "Some time in 2007, unless we've gotten a bit lost, but _definitely_ Cardiff."

Jack raised his eyebrows. Rose, leaning back against Jack's chest with his arms around her waist, looked dubious, which made Jack feel better about his own skepticism. "Doctor?"

The Doctor glanced up briefly, then back down at one of the screens on the console, which flickered with Gallifreyan symbols Jack had yet to decipher. "What?"

"What's in Cardiff?"

"The rift!" he answered brightly, as if that explained everything. Jack, who over the course of countless missions with the Time Agency and many cons on Earth had (to his knowledge) managed to avoid ever setting foot in Wales, did not find this a satisfactory answer.

"Great. What-"

"But we _closed_ the Rift," Rose interrupted. "I mean, Gwyneth did, and that was over a century ago. Why would it still be here?"

"Oh, it's closed, not _gone_. And in the meantime, it's leaking energy we can use to fuel the TARDIS."

Rose's expression only grew all the more skeptical. "You're joking."

The Doctor punched a button, frowned when nothing happened, and reached for the mallet he kept beside the console. "Did you think this ship ran on hope and happy thoughts?"

"And you mocked me for needing batteries," Jack muttered softly to her, smirking a little. Rose elbowed him, rolling her eyes and pulling away lightly.

"How long are we going to be here?"

"Ah..." The Doctor looked up thoughtfully at nothing in particular, unless somehow he thought he was going to find the answer somewhere in the intersecting columns of the TARDIS. "A couple hours, at least. You two should go on, wander around... by the time you get back, we'll be ready to go."

"Oh, yes, who could resist the opportunity to wander around _Cardiff_?" Jack muttered under his breath.

"The last time we were here, we met Charles Dickens," Rose informed him brightly, scooping up her jacket from where she'd draped it over a railing and bouncing toward the door the way she always did, whether they'd landed some time in the Middle Ages or her own time period or some time in the far-flung future.

"Do you think that's likely in 2007?" Jack asked as he followed her. He couldn't really help himself. Rose started off, and he followed, not least because there was the vague concern in the back of his head that if he _didn't_ follow her, if she wandered off alone, she might well end up dangling from a barrage balloon again. Well, probably not exactly that, especially in this time period, but there were any number of situations she could get herself into that _didn't_ involve barrage balloons.

"Probably not, but... things could happen."

"In Cardiff."

"You never know," Rose pushed open the doors to the TARDIS - and then stopped abruptly to turn around, Jack nearly running into her as a result. He almost tripped over his feet attempting to _not_ run into her, and covered by side-stepping, leaning against the door frame, and crossing his arms over his chest. He had a feeling it didn't work quite as well as he'd hoped.

"Aren't you coming?" Rose asked the Doctor, who still stood by the console.

"Oh, no." He waved them off with one hand without looking up. "I'm going to stay here and make sure the Rift doesn't do anything strange. You two go on."

"Are you sure?"

"Absolutely. You'll be fine. It's Cardiff, in the year two thousand and seven. What do you think's going to happen without me?"

Jack groaned and banged his head lightly against the door frame he still leaned against, closing his eyes. "I really wish you hadn't said that."

* * *

Jack flopped into his chair, more falling than sitting, and glowered at the calendar on his desk, like it might have maliciously placed itself there. In reality, it was probably Ianto who put it there - he seemed to think Jack needed the reminder, and every time Jack tossed out a calendar, a new one would discretely appear on his desk within the week. Jack was far more aware of the passage of time than Ianto could understand, and he didn't need to be reminded. Especially not of days like this.

He reached over to knock the calendar on its face and then switch on the CCTV monitor beside his desk. The screen flickered in shades of green and black before settling into the image just above the lift, and the TARDIS sitting directly on top of it. Jack stared for a second, his chest aching, before leaning forward again to turn it off. The picture faded back to black.

Outside his office, there was a thump as Owen set down a bag on the floor by his desk - Jack didn't want to know what Owen was carrying around to make that sort of a thump - and the distant sound of chatter as Tosh said hello. Jack paid hardly any mind at all, too focused on the presence of the Doctor on the street just above them. But it was the wrong Doctor, he was too early in the timeline and Jack was with him, younger and happier, and Jack already knew he didn't see the Doctor today. He lived through it.

It wasn't like he hadn't done this before. He and the Doctor and Rose had stopped in Cardiff to refuel a grand total of three times before the Game Station. The second time was in the 1940s, and Jack was nowhere near Cardiff at the time, so he hadn't had anything to worry, though he spent the entire day quiet and uncommunicative, staring at the sky and trying not to think of the future, his past. It was a quiet day, in the middle of the war, and he kept hoping that someone would start shooting at him, because even that would be better than having the time to think. The third time was a little over a year ago, with the mayor and the earthquake, and he spent the day locked down here, forbidding his team to leave the Hub if the world was ending. The first time was now, and it occurred to him that he should give his team the same warning now, because if they left and bumped into his younger self...

With a sigh, he levered himself out of his chair and started out of his office, into the main atrium. Gwen looked up at him as he stepped through the door. Owen, busy taking his time starting up his computer, and Tosh, staring intently at her own computer screen, did not. Jack reflected that he really needed to work on his commanding presence - he used to be able to just walk into a room and have everyone looking at him, immediately. Of course, back then, he didn't usually spend enough time with people for them to get _used_ to him... Still. It was something he'd have to look into.

"Alright, first things first - no one's going anywhere today. No one is leaving the Hub until you all go home for the night. I don't care if-"

"Jack?"

Jack grimaced at the interruption - so much for commanding presence - but turned toward Tosh nevertheless. "Toshiko. This had better be good."

"It is. I think." She gestured vaguely to the screen, frowning a little. "There's a police report that I think we should-"

"I was just saying we're not leaving the Hub unless the world's about to end," Jack said quickly, before she could continue. "Police reports don't qualify." Whatever it was, they could deal with it later. When the Doctor and Rose and a younger version of Jack weren't running around Cardiff.

"_Jack_," Tosh said firmly, shooting him a frustrated look over her shoulder. "It's from Aston Lloyd's flat."

He froze for a moment, and then walked over with a sigh, standing behind Tosh with one hand on her shoulder as he stared at the screen. "What happened?"

"Who's Aston Lloyd?" Gwen asked a moment later, walking over to stand at Jack's side.

Owen hadn't moved from his chair, and didn't look particularly inclined to. He flipped a pen absently in his hand, tossing it in the air and catching it over and over as he answered, "Some bloke who fell through the Rift a year ago, from... oh, about ten years in the future? Of course, we got to take care of him, find him a job and a place to stay, all that - more trouble than he's worth, if you ask me. What'd he do now, Tosh?"

"He's been attacked, and he's dead now."

Owen looked as if he were momentarily at a loss for words. "Oh."

Jack sighed. Just what he needed in his day. "Any mention of what did it?"

"Some sort of animal. The report wasn't any more clear than that, but I did find a CCTV feed by Aston's building, and..." Her fingers flew across the keyboard, too fast to see any individual keystrokes, graceful and assured, and in a moment an image popped up on screen, still for a second before a tap on the keyboard started it playing. Jack leaned in, studying the video. Just an image of an empty street in the middle of the night, streetlights and the fronts of a few buildings, cars parked on the side of the street... Nothing of any particular interest.

"So what-"

He stopped. Something dark and solid had flickered across the screen, too fast to recognize it, but something about the shape of it, half-registered, set off alarm bells in the back of Jack's mind, some ancient half-remembered threat...

"Rewind that and play it back frame by frame."

Tosh set it back thirty seconds and clicked through each frame individually. Nothing... nothing... still nothing... and then a blurry shape, which within a few frames resolved to a clearer image of _something_ very obviously not from Earth. Four-legged and lean, a thin body slung on even thinner legs, shoulder blades jutting up sickeningly from the body itself, each coming to a sharp point that slanted backwards. A spiky ridge along its back, and a narrow serpentine head, no tail or ears, all in all like some sort of twisted greyhound. Jack stared at it, willing himself to remember.

"It's on the video twice," Tosh said as she clicked through a few more frames. The creature's gait, even in slow motion, made Jack a little sick to look at, like all the joints didn't quite fit properly. "Once here, at about three AM last night, and then again twenty minutes later, just after Aston's estimated time of death on the police report."

Jack stared at the screen a moment longer, memory tickling the back of his brain. With his luck, it would be something from the two years he lost, something he knew he _ought_ to know but just couldn't put words or images to... A moment later, the image clicked with a name in his mind, and he let out a breath of mixed relief and annoyance. Of course that thing had to be here the same time as the TARDIS and the Doctor and...

It couldn't have _waited_ a day? A few hours, even... No, it couldn't be that easy, could it? Not for him, not on a day like this.

"I guess we are leaving the Hub today, then."

"End of the world?" Owen asked, eyebrows raised.

"Close enough."


	2. Stumbling Blocks

A memory is what is left when something happens and does not completely unhappen.  
-Edward de Bono

"Gwen and Owen, I want the two of you with me." Jack pulled on his greatcoat, shrugged his shoulders to settle it, and glanced around the atrium, trying to think. How the hell was he supposed to find one of those things in Cardiff?

"Who'd have guessed?" Owen muttered under his breath, though in the way he did when he _wanted _everyone to hear him. It was not at all subtle, but then again, Jack never thought it was supposed to be.

Gwen paused in the middle of fixing her gun to her belt and looked up at him. "What's that supposed to mean?"

"You never noticed every time there's some spiky dog alien or something, it's always 'Owen and Gwen, go take care of it.'"

"Yeah," Jack said, striding past him, "I'm a horrible person for asking you to do your job." Before Owen could make some protest about being a _doctor_, probably just for the hell of it, Jack went on, "By the way, it's not a 'spiky dog alien.' Tosh, I need you to track it from here, keep us updated o its position. It's an alien creation, something someone made - there'll be a signal for its owners to find it."

Gwen had started to trail after him, but Jack heard her footsteps stop abruptly upon hearing _that_. "Its _owners_? Are we going to have to find them as well?"

Jack shook his head dismissively without turning to look at her. "No, they don't ever leave home. My guess is, the creature fell through the Rift, and it's just lost. Tosh, the signal?"

Tosh gestured at her computer screen, which displayed a map of Cardiff marked by scattered colored lights. "You do realize that 'signal' covers over a thousand possibilities?" she asked, turning in her chair to face him and eying him skeptically over the top of her glasses. "I've narrowed it down to those associated with alien activity, but that still leaves over a hundred."

Jack sighed and ran a hand through his hair, leaning in to look at the screen. "Alright, I can see where that might be a problem. Uh... see if you can go back to last night and pick up a signal anywhere even close to where Aston lived, cross-reference it with what you're coming up with now. It'll be fairly regular, once a minute at least, simple - no information attached, just a signal it transmits so you can pick up its location."

"I can try," she said, and started typing. The colored map of Cardiff vanished, and was replaced my a mass of scrolling data. "Why would a creature give off a signal like that?"

"You know how some people put a microchip in their pets in case they get lost?"

Gwen whistled softly. "In that case, I _really_ don't want to meet the owners."

"Right there with you," Jack muttered, and took a step back. "Keep us updated, Tosh. I don't care how you do it, but _find it_. We've got to get out there before it attacks someone else."

That 'someone else', he had no doubt, would be one of three very _specific_ someones. But as long as they could deal with it before it ever found them...

He wondered, briefly, how many times he got the chance to save his past self without his past self ever knowing. The answer quickly came back: far too often. Calling his attention back to the present (a subjective term today if ever there was one), Jack noticed Gwen and Owen had started walking towards the lift, and winced.

"Not that way." Gwen and Owen both looked askance at him, so he elaborated, "There's something on the lift; we're going to have to go out the back."

'There's something on the lift', he decided, sounded better than 'There's a big blue box that travels in space and time on the lift'.

Jack turned away, toward the door, Gwen and Owen trailing behind him like ducklings. Rather heavily armed ducklings, sure, but close enough...

Gwen murmured a brief explanation to Ianto as they passed, but Jack didn't stop to listen. Out the door, out of the Hub, to the SUV and somewhere away from here, all while trying not to so much as glance at the TARDIS.

"So," Gwen said as the door of the SUV slammed shut after she climbed in, behind the driver's seat. "What is this thing, Jack? I know you know."

He sighed a little, clenching his hands around the steering wheel. After a moment, he answered simply, "Time hound." Beside him, Owen snorted and asked, "So when I said 'spiky dog alien'..."

"Close to the truth," Jack allowed, "it just sounded stupid." He reached up to touch his earpiece with one hand, turning the key to start the engine with the other. "Tosh, what've you got?"

It was impossible to completely ignore the TARDIS, always at least a blue blur in the corner of his field of vision. He tried to distract himself by thinking of everywhere he and Rose had been or would be today, so he'd know all the places to avoid.

And it was only when he actually tried to think about it that he realized he had absolutely no solid memory of the day at all.

* * *

Rose sipped at her soda, staring out the restaurant's window at passersby. She'd only been to Cardiff - or Wales at all - that once, with the Doctor, and it seemed odd to see the streets not covered in snow, to see electric lights inside instead of gas. That was the trouble travelling with the Doctor. You went somewhere you'd never been before, and whatever the time period, it froze like that in your mind.

Somewhere along the line, Cardiff had become the place where Dickens still lived. Seeing it in her own time, or near enough, was like seeing another city entirely.

"You know," she said to Jack, "the last time I was here, I almost got killed by ghosts. Me and the Doctor."

Jack looked over at her, eyebrows raised. "You said the last time you were here you met Charles Dickens."

"Who says I couldn't do both?"

"Fair enough." He leaned forward against the table, arms braced against the edge, chin resting on folded hands. "Unfortunately, I'm not seeing any ghosts today."

"They were possessing corpses. How is a normal day _unfortunate_?"

"Well, it would be breaking a record..."

"What record?"

"Everywhere I go with you two-"

Rose snatched up a napkin from the table and balled it up to toss at Jack's head. He ducked, naturally, and it hit the man sitting at the table behind him. Somehow Rose managed to suppress a giggle and pretend it wasn't her, focusing very intently on Jack instead.

"Oi, you can't blame us. We could've had plenty of perfectly calm trips before you came along. _You're_ the criminal here."

"Perfectly calm?" he asked, a smirk playing around the edges of his lips. She couldn't imagine why. Well, she had a couple guesses, but it was almost impossible to pin down why Jack was smirking at any given point in time.

"Yeah. It's _your_ fault that-"

"Besides the ghosts?"

"I didn't say they were _all_-"

"And the end of the world? Exploding government buildings? I could go on."

Rose rolled her eyes and leaned back in her chair, arms folded over her chest, pretending to be annoyed. Hard to do, smiling like she was. "I don't know why I tell you anything, honestly, if you're just going to use it against me."

"Because I am just that charming, and you'll tell me absolutely anything I want to hear. Which, while nice, is really unnecessary, just in case you were wondering - you've already gotten me into bed."

Rose laughed and leaned forward to shove him back, one hand on his shoulder. It was only a gentle shove, but he fell against his chair back a bit over-dramatically, laughing in that open, fearless, full-throated way that made people turn in their chairs just to see what he was laughing at, that always made her hear jump a little, made her want to grab him and snog him senseless, even though it usually ended up happening the other way around.

"Don't make me hurt you, Jack Harkness!"

"I might like it," he said with a grin. He opened his mouth to say something more, but something caught his eye through the window behind her, and the smile dropped off his face immediately, leaving no trace behind. "And the record goes unbroken," he muttered softly.

Before Rose could speak, he pushed his chair back, got to his feet, and started toward the door. Rose stared after him for a second, turned to look out the window, and saw absolutely nothing there out of the ordinary.

"Jack!" she called before he reached the door. "We haven't paid yet." It wasn't really what she meant to say, but somehow it was the first thing that came to mind. It was always ridiculous things that came to mind, times like these.

He stopped, just short of the door, and turned to face her, his hands spread. "No money!" He turned again and walked quickly out of the door, at a pace clearly meant to leave her behind, and she caught the just the faintest glimpse of _something_ on his face - uncertainty, concern, maybe even fear - before he vanished around the corner.

Rose growled in frustration and started digging through her pockets for money, muttering under her breath - mostly to herself, since there was no one else to hear or care. "'No money.' Between him and the Doctor... Might as well be travelling through space and time with a pair of five year olds, sometimes."

She finally located the pocket she'd put her money in (because at least _she_ remembered these things when leaving the TARDIS), pulled out what she hoped would be enough, and tossed it on the table without counting it before running out the door after Jack. Once outside, looking up and down the street, she decided it was time to start plotting ways to kill him. How could he manage to disappear completely in less than a minute? Unless he used that stupid wristband... and she really would kill him if he did...

A movement out of the corner of her eye caught her attention, and she turned to see him striding down the street, away from her. Even from behind, she couldn't mistake him - nobody moved like Jack, strong and graceful, like some sort of great feline - though where he'd gotten that blue coat when he hadn't been wearing it before, she didn't know.

"Jack!" she shouted, and took off down the street after him. As if he could _really _just walk away from her _that_ easily...


	3. Cross Step

Tell me with whom you go and I'll tell you what you do.  
-William Blake

"Jack!"

He thought the shout was in his head at first, something he imagined. A memory, or the echo of one, coming back. Actually, he _hoped_ it was a memory coming back, because _any_ memory of today would be better than none at all. Funny thing about memory - you never knew what large chunks could be missing until you went looking for them specifically. And then it could get a little frightening.

"_Jack_!" Louder, more annoyed, and _closer_, and now he realized it definitely _wasn't_ in his head - no mistaking that he'd actually just _heard_ that. He stopped and turned quickly, coat fanning out behind him with the sudden movement. She'd almost caught up by then, and he had time only to register blonde hair, a pink shirt or jacket, and a very annoyed expression before her momentum carried her straight into him, thumping against his chest before she could slow down, much less stop.

Jack reached out instinctively to steady her, hands on both her shoulders, and this was familiar, he _remembered_ this. Not specifically, from one day, one trip, but a hundred different times, holding her gently upright even when she might not need it, the automatic tilt of his head to try and catch her eye, to verify that she was alright.

Rose took a step back and brushed her hair back from her face, laughing as she looked up at him. "What in the _world_ was that for?"

His heart plummeted to his stomach and stayed there, an acrid taste rising in his throat at the same time. He remembered this. He remembered _her_. But this wasn't a memory, she was standing right in front of him, grinning like she always used to, so terribly young.

He also remembered looking through reports of the dead at Canary Wharf, and seeing the one name that mattered: ROSE TYLER.

He was standing here looking at a dead girl.

He ought to say something, he knew, but somehow the words wouldn't come. At least, not until Rose raised her eyebrows at him, uncertainty creeping in. Jack knew exactly the expression she'd make before she made it, chin ducked slightly, lips pressed together, brows just slightly furrowed.

"Seriously, you can't just run off out of nowhere, make me pay, and then not say anything." She tried for a light tone, but worry tainted it, like blood in clear water, and he couldn't possibly miss it.

This would all be so much easier if he could remember what the _hell_ he did today. He reached for the memory, and it sidled away, just out of reach. "Sorry, I was just-"

Something else sidled into his field of vision, just in the corner of his eye, and out again just as quickly. Gray and blurred, maybe imagined, but it cut him off as he whirled to look down a mostly empty street, just one car calmly cruising past. There was a possibility it wasn't there at all, but if it looked like a Time Hound...

If it looked like a Time Hound, chances were the nearest two people out of their proper timeline should get the hell out of Dodge. Or to the nearest safe place, which right now meant the Hub, or...

"We need to get you back to the TARDIS," he said, taking her lightly but firmly by the arm, pulling her down the street and praying to whatever powers that might exist that she wouldn't argue.

Clearly, he'd been away from Rose for far too long if that possibility even crossed his mind. She planted her feet and stopped walking. He managed to pull her a few more steps out of momentum, but she always did have the most amazing ability to fix herself to one spot and make absolutely certain she wasn't moved without a level of force Jack wasn't entirely comfortable with when it came to her. Still holding her arm, he pivoted to face her. "What?"

"You can't just swan off and leave me on my own one minute, and _then_ suddenly decide it's so important that we go back to the TARDIS, and still not tell me what's going on! So I'm standing here until you explain it to me, and _then_ maybe I'll go back."

The maybe in that sentence worried him. Not as much as the part before it, though. _Why the hell did I try to leave her alone? In Cardiff? I couldn't have been that stupid even then..._

He released her arm, but only so he could gesture pointedly at her, as if being extra emphatic was going to get his point across. "There's something here. A... something that fell through the Rift, from another planet. And it's _really_ not safe for you to be out there with that thing on the loose. I'll tell you more when we get back to the TARDIS."

No, he wouldn't, he'd just wait until she got inside and then disappear as quickly as possible, but whatever it would to take to get her there...

"An alien?" Rose asked, frowning a little. Her expression didn't change beyond that. Not a good sign.

"If you want to call it that, sure. An alien that's going to want to kill us. So can we go now?"

"And what, just leave an alien to run around Cardiff?"

Jack growled, resisting the urge to pick her up and just _carry_ her. That wouldn't go over well, though if it came down to it... "It's not going to hurt anyone except _us_!" And the other version of him, and the Doctor, and anyone else who'd ever travelled in time, but that didn't seem quite as important at the moment.

Rose studied his face silently for a moment, and then folded her arms over her chest. Internally, Jack groaned.

"So this alien that wants to kill just us. Tell me about it."

* * *

One useful thing about being a former Time Agent - one of the useful things that didn't make the Doctor look at Jack like he was a dog that might need to be put down - was that Jack knew well just about every creature that preyed on paradoxes, anomalies in time, people out of their proper timeline. This one... not as bad as reapers, but not the sort of thing you expected to see running around twenty-first century Cardiff. Not the sort of thing you expected to see _anywhere_ off their home world, and wasn't that the point?

Jack jogged down the street, not fast enough to draw too much attention to himself, more than fast enough to outdistance Rose. If one of them was going to be attacked, at least it would be him... which wasn't really that much of a comfort, come to think of it. Still, what the Doctor would do to him if it attacked Rose...

He checked his belt for his sonic blaster - still there, so at least the Doctor hadn't seen fit to steal it before Jack walked out of the TARDIS... That would make this easy. Not so hard to kill, time hounds, provided they didn't surprise you and you had the proper weaponry, though how he was going to hide the body afterwards... well, that was what teleports were for. His hand moved to his wristband next, flipping it open and setting up a quick scan - not necessarily for alien tech, but there should at least be a signal...

"Jack!"

Not a voice he recognized. Not at _all_ a familiar voice, and unfamiliar voices calling his name always did put him on edge since he left the Time Agency. Then again, it was the wrong name if _that_ was the explanation.

Jack flipped the cover of his wristband shut and spun around to see two people coming down the pavement toward him, a man and a woman, both armed, he can tell at a glance, though they've got the weapons concealed. No immediate signs of being Time Agents - the clothes all match the time period, no wristbands, and he's tempted to scan them, but there's no way to do that right now without being obvious. Most importantly, no one he recognizes, no one who should know his name, especially _this_ name, when he's only been using it since World War II...

He put on a bright, false smile and let his hand fall away from his wrist, conveniently now at the level of his sonic blaster, not that they'll notice that unless they're as adept at picking up that sort of thing as he is. Few people are. "What?" Safer question than most others he could ask, probably better than trying to tell them they've got the wrong person, definitely better than asking who they are.

He just manages to shove back the annoyed thought that he doesn't have _time_ for this.

"What," the man repeated in disgust, in an accent very definitely not Welsh. "Drags us out here, runs off, and now he says _what_." Jack got the impression this was the sort of man who spoke just because he didn't like the sound of silence. Also that he'd better say something now, or this might go on.

"I'm sorry." He didn't know what he was apologizing for, of course, but they seemed to think they knew him, so chances were an older or younger version of himself had something to apologize for.

"That's a change," the man snorted, and Jack raised an eyebrow. Maybe apologies weren't the way to go, and his guess was starting to lean toward "younger him". Great. In the way that could very easily end in disaster and a paradox swallowing them all.

Or maybe just him.

"You could have waited until we got out of the SUV," the woman scolded, stopping in front of Jack and giving him a reproving look. "What, did you see the time hound?"

Jack stiffened, not quite visibly, and revised a few initial judgments. Maybe they were Time Agents after all, but the lack of wristbands, the name they called him by, the way they spoke, the way they _moved_ was all wrong. Names, he decided, might help. Not a lot, but it would give him _something_.

"Yeah. Lost it, though - moved too fast. You picked up anything on scans?"

The man reached up to touch an earpiece and asked, "Tosh, anything?" There were more of them. Better and better.

The woman was still watching him in a way that couldn't help but make him nervous, big dark eyes suspicious from underneath her bangs. "What happened to your coat? Weren't you wearing it when we left the Hub?"

_Damn. What the hell is a Hub?_ "Left it in the car. Had to run in, especially in this weather." He tried a smile that worked to distract people from the obvious questions maybe fifty, sixty percent of the time on a good day - it had worked on Rose, after all, in World War II. The way the woman was _still_ looking at him oddly... this seemed to be a different case.

Jack considered for a second, whether he should say something more or let it drop and hope she would too. "Well," he said finally, deciding a change of subject was the way to go, "we're not getting anything done standing around here. I'll track the time hound with my wristband, and the two of you can–"

"Wait!" the man said sharply, one hand still to his earpiece. Jack glared half-heartedly, somewhat annoyed to be interrupted, but at least it distracted the woman from _watching_ him like she was trying to divine his deepest secrets from simple visual cues. He found it... more than a little disconcerting, not least because he wasn't entirely certain she _couldn't_.

He waited a moment, impatiently, for whatever communication happened to be coming over the headset to finish, and finally asked, "If you're done–"

The man's head jerked up, gaze fixing on something behind Jack, and Jack cut himself off. The man's hand dropped, moving for his gun. Assuming the intention wasn't to shoot _him_ and hoping he was right, Jack spun around.

He'd never actually _seen_ a time hound before, in person. Just pictures and holographic recordings. None of that completely conveyed the unsettling way they moved, like a set of bones loosely arranged and unconnected inside a sack of skin. Of course, that mattered less than how _fast_ they were when one of them was lunging at his face.

Jack dropped instinctively into a crouch, because when it came to time hounds, rule number one was _get out of their way_. It tried to turn mid-leap, and mostly failed, though a claw tore through his shirt and raked a gash in his back. _Great._

He rolled onto his back, ignoring the pain, before the creature could regroup, reached for his sonic blaster - and then noticed both of the maybe Time Agents reaching for guns. Which immediately negated any chance that they might actually be Time Agents, because... _really_? Guns? Jack whipped his blaster up and snapped, "Don't!", hoping he'd get off a shot _before_ the idiot twins managed to.

Of course, in the typical way of his life since he met the Doctor, he didn't.

Two gunshots rang out, one a deep roar, the other one not quite as loud but very distinct. _Stupid._ One missed completely, as the time hound writhed, serpentine, out of the way. The other ricocheted off armored skin, dipped Jack in the shoulder, and just made the thing _angrier_. It turned its attention from Jack to the not-Time Agents, sprang with hooked teeth bared...

A sonic blast knocked it away before it reached either of them, sent it tumbling as Jack struggled to his feet. Not enough to kill or even stun, no time to change the settings, but enough to _hurt_, at least. The time hound skidded on its side, jumped up while Jack fought to find a setting on his blaster that would kill the thing... and it was gone.

"_Fuck._" Of course it would run away. At least three temporal anomalies here, counting the Doctor, not counting the TARDIS, why not go for the ones that _weren't_ going to shoot it? Jack clapped a hand to his shoulder, determined the wound wouldn't kill him even if it hurt like _hell_, hooked his blaster back on his belt, and glanced to the two kids - both looking at him like they expected instructions. Why did things always have to get complicated?

But at least one of them could track the thing...

"You two," he said, already turning down the street while the muscles in his back and shoulder screamed, "put those away and come with me."


	4. Run to Ground

Memory is a way of holding on to the things you love, the things you are, the things you never want to lose.  
- Kevin Arnold

Jack held open the door of the SUV for Rose as she climbed into it - less from a sense of chivalry than because if a time hound came lunging at her out of nowhere, he'd like to be in a position to intercept it rather than on the other side of the vehicle. Not that the chivalry hurt. Or maybe it did. His heart had twisted painfully at the way she smiled at him, when he moved for the door in the first place, and he slammed the door as soon as she was settled, turned away as quickly as possible.

That was the thing with being immortal and stuck in one timeline. Sure, you had to watch everyone die, but at least that was almost guaranteed to be the _end_. You weren't supposed to see the dead _again_, younger and smiling, remember the feeling of their hand in yours or the smell of their skin so clearly because it was _right there_ and real... Jack wondered how the Doctor ever managed.

He shook his head, shook the thought away, and focused on more important questions. Like where he went from here, with that thing on the loose. He should take her back to the TARDIS, but the TARDIS would just be a beacon for the time hound, and if it was already there...

Jack let out a breath and started around the front of the SUV. Other questions to worry about. Like where the other Jack was, the Jack that belonged with Rose. Could still be on the TARDIS. If he wasn't, though... if he got too close... He did not want to meet the Doctor again because he just created a paradox. He'd rather not meet the Doctor at all, actually, not this way, not in his past, not on a day he couldn't remember. Not the TARDIS, then. Get Rose somewhere safe, worry about getting her back after the time hound was taken care of. Which meant he'd have to trust...

"Toshiko!" he said into his headset as he pulled open the door, swinging into the driver's seat and pointedly not looking at Rose. "Tell me you managed to get that tracking system in place."

"It's working, but there's only so much I can do when the signal's only coming in once every few minutes." He'd have pressed it, but he recognized that 'please don't sak me to do the impossible' tone from her, and just sighed. "The last thing I got from it, the creature was... a little over two hundred metres northeast of your current location."

Jack let out a breath as he started the car, doing a few quick mental calculations. Time hounds could move fast, but they'd have some time, if they just kept moving... "Keep me updated, and make sure Gwen and Owen keep after it. Their guns won't work, but if they pull those energy pistols we picked up last month out of the-" He stopped himself, just biting back a curse. He had the SUV. Wonderful.

"Gwen and Owen? Why aren't you-"

"Not important. Call Gwen and Owen back to the Hub, have them grab a containment unit, any sort of non-ballistic gun we've got around... just do it, quick as you can."

He cut off the speaker on his headset and focused his attention on the road, but only managed for a second or two before Rose cleared her throat. Jack glanced over at her reluctantly. She'd folded her arms over her chest, eyebrows raised, just _waiting_. "Well?"

Jack looked away. "Well what?" He didn't really think that if he kept asking questions, he would be able to avoid this conversation, but he could damn well try.

"What's with the coat? And the... headset and the car? What's going on, Jack?"

He grimaced, glanced at her again for just a second. "Rose, trust me when I say I couldn't begin to tell you."

"Is it... something to do with Time Agents? Is that who you were just talking to?"

He snorted a little despite himself, startled into an almost-laugh. "No."

"So what is it? What's going on and... where did you get this car?" She leaned back to peer over the seat at the computer systems installed into the back, where Toshiko could access them when they were all in the car together, and Jack grimaced. He'd forgotten how many questions she could ask, and how _damn_ persistent she could be.

"It's a long story," he said, which they both knew wasn't an answer at all. He saw her open her mouth, probably to say just that, and added somewhat reluctantly, "I'm not who you think I am."

Rose stopped, glanced out the window for a second, and then back to him. He noticed her hand moving for her pocket, probably just in case she needed to grab her phone, and smiled grimly to himself. "So what is this, then?" she asked, eying him with a mixture of confusion and suspicion. "Oh my God, are you kidnapping me?"

Jack laughed again, a little more genuine this time. "Only for your own good." He paused, winced, and added, "That came out wrong. There's just... something out there, a creature I know for a fact will kill you if it finds you."

"So what is it?"

"Long story."

"Stop saying that!" He didn't answer, and Rose considered him for a moment - Jack didn't turn to look, but he could feel the weight of her gaze, guess at her expression, bottom lip between her teeth, frowning ever so slightly. Finally, she asked, "So if you're not Jack, who are you?"

"Captain Jack Harkness," he answered immediately, and it surprised him a little that it came out with no special emphasis, the same casual tone he'd use for any stranger he met on the street.

"But-"

"I said I wasn't who you thought. Not that I'm not..." He drew a breath, let it out with a sigh. "Rose-"

Tosh's voice on the comms cut him off. "Jack, I think you might have a problem." Jack bit back a curse.

"Hold that thought," he said to Rose. Into the headset, he answered, "What's going on, Toshiko?"

"I think it's following you. At least, the last two times I picked up the signal, it's been nearer to you. Or if you want to be more specific, the signal I got from your headset, although Gwen swears you're with them. Jack, it would help if-"

He cut off the headset and hit the gas, hard, whipping the SUV around a slower-moving car with casual disregard for a number of traffic laws. No time to explain to Toshiko, no time for the distraction. With a time hound chasing, the only real thing to do with the equipment he had on hand was _run_. Run and hope Gwen and Owen took care of it before it caught up. Hell of a chance to take.

"Alright, Rose, I need you to listen to me, and we don't have a lot of time, so don't ask questions."

"Fat chance of that!" she retorted. "You haven't given me one real answer yet, and if I don't get one soon, I _swear_, you're stopping this car and I'm getting out."

"Fat chance of _that_," he answered, shooting her a glare. "You sticking with me is what's going to keep you alive now."

"What's going on, then? Who _are_ you, and I mean it, if you tell me-"

"I'm from your future," he snapped, without turning to look at her, as he took a quick turn around the corner, tyres bumping over the kerb. That was the key, keep moving, keep changing direction, maybe it wouldn't be able to keep up, maybe they'd be able to leave it behind. "Further along on our timeline. I've lived this day before, Rose."

She stared at him for a minute, like she was trying to decide if he was serious, and only stopped when he took a sharp turn and she had to whip her arm out and catch herself on his shoulder to keep from tipping over. "So there's two of you here? My Jack and you?"

He managed not to wince at the words "my Jack", managed not to snap at her that he _was_ her Jack, the same man a century on. He just nodded. "Yeah."

"Isn't that a paradox?"

Jack smiled faintly. "As long as you - the three of you, I mean - don't stay here too long, and I don't get too close to myself, we should be fine."

"That must be disappointing for you," she said, grinning at him. His heart somersaulted. "Not being able to get too close to yourself."

Jack swallowed a lump that felt like his heart - the memory of her smile was one thing, but this... - and smiled, bright and false. She didn't seem to notice it was put on. Maybe a century did make that much of a difference. "It's a fact I've _often_ regretted."

"So if it's not a paradox, what are we running from? It's not one of those... big bat things, is it?"

"Like I said, not unless I touch myself." She shot him a look, like she thought he was making some kind of joke, and he smirked. "You know what I mean, and I don't plan on it. Luckily, our problems are just a _bit_ smaller than that right now." As much as he hadn't _wanted_ to tell her all this... now that he was, it simplified things. Easier to focus on the facts, instead of the knot of emotions tightening more and more in his chest.

Facts. Focus on that. Hard to forget the fact that there was a time hound chasing them, after all... He considered switching his headset back on, finding out where the time hound was by now, but if Gwen and Owen were telling Tosh they were with him... Too many explanations to make, not enough time. He'd deal with that later.

"Time hounds!" he announced, maybe a little louder than necessary. "Actually, time hound, singular - it fell through the rift, just the other day, or it would have come after me sooner. The Doctor's timing is... interesting, as always." Rose smiled a little at that - no one who had _met_ the Doctor could argue that - and Jack chuckled before going on. "They only exist on a planet... a very long distance and several thousand years from here, except when the rift decides to throw us for a loop."

"And it's chasing us because...?"

"Because we're outside of our proper timeline. They didn't evolve naturally, time hounds - they were created specifically to hunt... well, Time Agents. It's a long story that's a good cautionary tale about why we don't irritate talented genetic engineers, but we don't have time for it. The point is, they're strong and fast, they're more or less immune to conventional weapons, and they can-"

The sudden silence as the car's engine died abruptly made him stop. It took him a second to process it, just what that absence of sound meant, and then his heart sank. It meant the time hound had almost caught up.

"They can do that," he said, hitting the brakes and pulling the car to a quick stop in the middle of the street as he took a quick survey of the surrounding buildings. Where the hell were they anyway? Some flats, shop on the corner... no handy warehouse that he could see, which almost surprised him. "Another reason you don't irritate talented genetic engineers from certain time periods. Sometimes they've got some really nasty tricks up their sleeve."

"Did it just kill the engine?" Rose asked, already undoing her seatbelt and starting to tumble out of the car. Jack followed a second later, circling around before the time hound could appear and... No time to consider that. If it could kill the engine, how far away could it be? How much time until...

"Got it in one," he muttered, grabbing her by the arm and pulling her toward a flat that looked like it might be abandoned, windows and doors boarded up. Fast as they were, strong as they were, get a few solid doors between a time hound and him and it should at least slow it down a bit. And what then? It would find them no matter what he did, and-

And he'd deal with finding a plan as soon as they weren't on the open street and vulnerable. He reached the door, kicked it open and ushered Rose inside - his initial assumption that the flat was abandoned was, thankfully, correct. One point for him. About one hundred points for the thing with speed and homing capabilities and very sharp teeth on its side.

"What do we do next?" Rose asked, spinning to face him as he dragged a dusty, battered table from against a wall to block the door. One more thing to slow down the time hound.

"I'm working on that," he growled through clenched teeth.

"But you've done this _before_! Shouldn't you know how we fix it?"

Jack grimaced and looked up to meet her eyes. "That's the thing - I don't actually remember what happened, and even if I could... what do you want to bet today's timeline's flexible?" Not the most encouraging thing he could have said, as Rose stared at him and his own heart sank slowly... He did remember she survived. That could change today. "Help me barricade the door."


	5. Collide

It is a poor and disgraceful thing not to be able to reply, with some degree of certainty, to the simple questions, 'What will you be? What will you do?'  
- John Foster

First rule of time hounds - even if Jack hadn't just learned it first hand - was that they were fast. Fast enough to force you to rely on reflex, fast enough to kill you if your reflexes weren't good enough. Jack knew perfectly well that they had not a chance in hell of catching it on foot - at least, not if he wanted to find Rose alive and in one piece afterward.

Jack yanked open the driver's side door of a car unfortunate enough to try to park near him, hauled the driver out unceremoniously with his uninjured arm, and slid into the driver's seat before the man could argue.

"Sorry, I need this. You'll get it back." Probably left on the side of the road somewhere for the police to find, and with a few bloodstains on the upholstery, but Jack considered those minor details. He closed the car door.

The woman, as she pulled open the door to the passenger's side, flashed some sort of identification. "Torchwood. We're _very_ sorry, it's an emergency."

She got in, shut the door, and gave Jack a reproving look. He ignored it, as he ignored the driver now standing on the pavement shouting invective, and took off as fast as the car would go. Probably faster than technically legal, but it was comforting to know that he couldn't actually disregard any traffic laws if he didn't _know_ the traffic laws of this time period in the first place.

Jack realized, after a moment, that she was still staring at him. This girl had eyes _made_ for reproving stares. "What?"

"Who are you?" Simple as that, somewhat accusing, more than a little suspicious, and he couldn't help noticing that her hand was close enough to her gun to... Well, shooting the driver of a fast-moving vehicle was probably a bad idea, but she might threaten him with it if he gave the wrong answer.

"Captain Jack Harkness," he answered, glancing briefly at her, and then over his shoulder at the other one. "Listen, I need you to tell me-"

"No you're not."

Jack stopped to give her an incredulous look. Why even bother _asking_ if she was just going to tell him he was wrong? "Yes, I am."

She frowned at him, clearly disbelieving, but the man in the back seat snorted and said, "Sounds like Jack alright."

Jack growled a little under his breath. "Look, you're obviously from a different point on my timeline, and I don't have the time to figure out when and why. What's your name?" he asked the woman.

"Gwen Cooper."

"Good. Your name?"

"Doctor Owen Harper."

Rather than question if the title was really necessary now, Jack just rolled his eyes and went on. "Okay, Owen! You're in touch with someone tracking the time hound - you're going to keep me updated, because we need to find it before it finds someone less capable of handling it."

Less capable than him, anyway. He wasn't counting on the two whose first instinct was to shoot it with _bullets_.

"Gwen... You're going to need to stop talking to me."

"Good luck with _that_," he heard Owen mutter behind him, and then in a different tone, over his comm, "Tosh, where is it now?"

Gwen ignored Owen, all her focus on Jack, and for once, he wasn't entirely sure he was comfortable with that, under the circumstances. Ordinarily, a pretty girl with eyes like hers paying that much attention to him was the start of a good night, but... "What do you _mean_, a different point on your timeline?"

Jack grimaced. "What did I _just_ say?"

"You can talk and drive at the same time!"

"Actually-"

"West of us," Owen called out from the back seat. "Couple hundred metres."

Jack took a turn, hard, tyres squealing, and came within inches of sideswiping another car. Gwen fell hard against the door before regaining her balance, one hand now on the window to steady herself, and Jack smirked over at her. "I tried to tell you. I've never actually driven anything with an internal combustion engine. But I'm a quick learner."

"Alright, that's it. Stop the car, I'm driving."

"We don't have that kind of time." He took a breath, and took his eyes off the road long enough to glance at her again and smile, hopefully more reassuring this time. "Relax. I know what I'm doing." Mostly. Enough. He turned his attention quickly back to the road.

She still had one hand on the car door on her side, the other on the dashboard, like she was half bracing herself for another sharp turn. "Who are you really?" she asked at length.

This time, Jack didn't turn to look at her, just answered, "Jack Harkness, and please don't tell me I'm not. We've gone in circles enough here."

"Take a right!" Owen called, and Jack did so without hesitation. On reflection, he probably should have hesitated a little to check for pedestrians and street signs, but he hadn't hit anybody, and they could replace that street sign... The car might be a little dented, but again. Minor details.

"Careful!" Gwen scolded, and he caught a glare out of the corner of his eye. "I swear, if you hit anyone..."

"I won't!"

"You bloody well drive like him, at least," she muttered, not quite under her breath, and paused, seeming to sort through any number of questions before she settled on, "You look younger. Different hair."

He expected older more than younger, and took a moment to decide how to respond. "Sorry. It happens, time travel and all..."

Owen leaned forward, taking his attention from the comms for a moment. "Did you say _time travel_?"

Were he not driving, Jack would have closed his eyes and leaned forward to rest his head against the steering wheel out of sheer exasperation. As it was, he just groaned and tightened his grip on the steering wheel. So he - the older him, whoever he was, whatever he was doing in this city, in this time - hadn't told them about that. This just kept getting better and better.

"Time hound," he snapped, in lieu of an actual answer. "Where is it now?"

"That's not really going to keep that thing out, is it?" Rose asked. Table in front of a door wasn't much of a defense, especially when those boards on the windows didn't look too sturdy. She took a step back, glancing around the room. Stairs, an open door to what looked like a kitchen in the back - or what had been a kitchen, when this place wasn't falling to pieces - another door to an empty room with more boarded up windows...

"Not for long," Jack said, already turning his back on the door, taking stock of the room just as she had. "Long enough, if we're lucky."

"And if we're not?" she asked, knowing she probably didn't want the answer.

Jack eyed her for a moment, expression unreadable, and then shrugged, forcing carelessness. It wasn't as obvious as it would have been with her Jack, but she knew it when she saw it. "Hope you're not too attached to having a throat."

Rose grimaced a little, wrinkling her nose. "Charming."

"Hey, I didn't design them."

He walked quickly to the door to the kitchen, glancing up the stairs as he passed them, and into the kitchen when he reached the door. "No back door - we're not getting out that way."

Rose followed him, keeping an eye on the door and the windows just in case. Though now she was a little worried about the stairs, since Jack looked up there - that time hound thing couldn't possibly jump high enough to break through a second floor window, could it?

She hesitated for a moment, watching his face, while his lips moved as if working out some plan to himself. He looked older. Tired. Even his smile... "This probably isn't a good time to ask, but... I don't think it's going to get any better..."

Jack frowned a little, glancing over at her, and drew a breath. "I think any time would be better than while we're waiting for an alien dog to come and try to _eat_-"

"What happened?"

If she let him go on, he'd never let her get the question out, so she just asked, riding over anything he might say. Jack froze for a second, only the slightest change visible in his eyes - surprise, then anger, pain, and it was that last he couldn't quite seem to chase away. It had been there before, but now it deepened, intensified, and Rose swallowed hard, forcing back the dull ache that sprung up in her chest looking at him now.

"What?"

"I thought... I mean, the three of us, we were supposed to be-"

"Rose," he said, sharply enough to cut her off, and gave her a hard look. "You know I can't tell you that. Even if-" He faltered for a moment, and then shook his head. "This is all in my past. If I tell you, you'll only want to change it, and you _can't_. Just trust me, you _don't_ want to know."

"If I didn't want to know, I wouldn't have asked! Look, just-"

The door shuddered with sudden impact, jarring it enough that the table blocking it slid inward a few inches, allowing the door open a crack. Rose had expected some noise, barking or growling - hound and all that - but there was nothing, just a thin, toothy snout pressing itself against the gap, and she could only see a nose and skin and teeth but just looking at it, it was obvious it was like no dog she'd ever seen before. The nose withdrew after a second, and the time hound slammed against the door again after a second, even harder than before.

Rose took several steps back, glancing around for anything she might be able to use as a weapon. Not that it'd do much good, from what Jack had said, but she wasn't just going to stand around to be mauled.

"It's going to get through that door," she said, keeping one eye on the door as the time hound hit it again and the table moved another inch or two.

"I know." Jack pulled out a gun - an old-fashioned pistol, not the blaster she was used to from him - and took a few steps toward the door, placing himself between it and Rose. She tried not to think about how he'd said guns wouldn't work on this thing.

"Any brilliant plans?"

"There's a fire escape from one of the windows upstairs," he said, with a nod to the stairs. "You're going to run, I'll stay here and deal with the time hound."

She stared at him. "You're joking."

"I'm really not."

A slender leg pawed through the gap between the door, clawing at the door, the table, the floor - looking at it, it didn't look quite right, like the thing was nothing but skin over a skeleton. Rose shook her head slowly. Running off while he stayed here and got his throat torn out didn't exactly seem like a plan to her. "I'm not leaving you."

He turned to meet her eyes for a second, and gave her a tiny, bitter smile. "You say that now."

"...What?"

Jack took a few steps toward her, took her by the arm, and pushed her gently toward the stairs. "Rose, _go_. Find the TARDIS, find the Doctor, find the other me, just _get out_."

She looked up into his face, and the words that came out when she spoke weren't the words she meant to say. "It's gonna kill you."

For a moment, he didn't answer, and then he grinned at her, cocky and dangerous and _this_ was the Jack she knew, for just a moment. "We'll see about that," he said, and gave her another light shove toward the door. It was enough to carry her a few steps toward the stairs, just as the time hound hit the door again with an impact that echoed in the empty room, and something lean and corpse-gray slipped in through the partially open door, moving so fast it blurred.

Instinct propelled her up the stairs despite her reluctance to leave Jack alone, down the hall and to the room with a fire escape, just like Jack had said, out the window and down the fire escape while gunshots sounded behind her, and though she listened, the time hound didn't make a sound.


	6. Walk Away

I think history is inextricably linked to identity. If you don't know your history, if you don't know your family, who are you?  
-Mary Pipher

"This building, on the left!" Owen called from the back seat, a little louder than Jack thought was strictly necessary. He glanced to the left, spotted a blonde girl racing down the fire escape of what looked like an abandoned building, and hit the brake hard on instinct before conscious thought even had a chance to kick in. They all lurched forward, Owen falling against the seat in front of him, Jack nearly thumping against the steering wheel. Gwen, who had taken the opportunity to put on her seatbelt earlier while muttering about the likelihood that they would all crash and die, was fine.

Jack could have taken a moment to recover, but instead he shoved open the car door without even turning the car off (or putting it in park, he realised a moment later, though he noticed Gwen reaching over to do that out of the corner of his eye) and raced for the fire escape, just in time to catch Rose at the bottom. Well, maybe catch wasn't the right word. It was more like she jumped the last several feet to the ground and thumped into him, almost knocking them both over.

Jack caught himself before falling down, wrapped his arms around Rose to steady her too, and let out a relieved laugh, pulling her into a hug. "Rose! You're alive!" He winced as soon as he said it. It was generally best to avoid pointing out that her survival was ever in doubt in the first place.

"Of course I'm alive," she said, pulling away from him without hugging back - which was enough to give him pause. "Not sure you will be in a minute..."

Jack stared at her, as she started for the open door of the building she'd just run out of. Now that he looked at it, the door was open. No, _broken_, more than open, like something had... battered it down... "_What_?"

"There's another one of you here, no time to explain, will you just _come on_?"

Jack swore a little, because of course it wouldn't be so simple as just getting her to safety. Not with Rose bloody Tyler, always determined to save the universe or just one little person, whatever she could manage. And of course she'd had to run into _him_, past him, future him, whichever, he was almost certain he'd rather she didn't know him at that point in his life. He rushed into the darkened building after her, just as Gwen and Owen tumbled out of the car and raced after _him_ like a pair of very purposeful puppies, guns in hand.

Rose started a little, hearing their footsteps, and blinked at them for a second, though she was still moving into the house. "Who-"

"Rose," Jack sighed, "meet Gwen and Owen. Someone will explain later." Hopefully someone not him. Though he'd settle for a version of him who happened to know what the hell was going on.

Rose eyed the two of them dubiously, while Gwen and Owen stared at her with "who the hell are you?" expressions Jack was almost certain perfectly matched the one he'd given them not that long ago. Rose finally swung back toward Jack with an expression that was not in the least encouraging itself.

"You run off and leave me on my own while there's some mad snake-dog... _thing_ on the loose, and then while I'm busy running for my life, you just go... swanning about picking up strays?"

"There's a difference between swanning about and trying to..." He trailed off as Rose turned away again and continued into the building, paying barely any attention to him. He grimaced and glanced to Gwen and Owen before following her, trying to ignore Owen's raised eyebrows, Gwen's bemused smirk. Neither of them were his problem, at least until some fuzzy far future. He'd worry about their opinions and questions _then_.

"You could have told me about the vicious dog thing _before_ you ran off," she said over her shoulder.

"I was hoping I'd be able to-"

"Oh, getting him to tell you anything important is like pulling teeth," Gwen said with a teasing smile. When Jack turned to frown at her, she added, "From a bear."

Owen snorted. Rose grinned at Gwen, while Jack scanned the room in an effort to ignore them all. He took note of the way the hinges and lock on the door looked damaged, a heavy table stationed near it at an angle, the paint on the door scraped like the door had been used to push the table aside... No sign of anyone still _here_. Except... now that he listened, those could be footsteps upstairs, slow and cautious...

"Am I the only one who hears that?" he asked after a moment.

Gwen and Rose stopped, and Owen frowned, cocking his head to the side as if listening intently. After a few seconds, he shook his head and rolled his eyes. "Nah. Though knowing you, Jack, it could just-"

Gunshots sounded upstairs, three sharp, distinct cracks of a revolver, and a half-second later, something heavy thumped against the wall upstairs, then the floor. All four of them lunged for the stairs immediately, moving on instinct a few scant heartbeats after they registered the sound.

Jack paused at the top of the stairs, taking a second to orient himself and sort out just which room the noise had come from. Rose didn't hesitate for a second, barreling past him and down the hall toward what looked like it had once been a bedroom, before the flat was abandoned. "Jack!"

They hit the open door all at once, Rose just a few steps ahead of the other three, so she slipped into the room easily while they jammed momentarily in the doorway. It would have been comical if it weren't for the angry predator inside the room.

Jack lay flat on his back on the floor, a nightmare on top of him, claws digging into his shoulders and making a bloody mess of his coat, revolver on the floor halfway across the room. He'd wedged a hand into the space between the front of the time hound's shoulder blade and body, which gave him just enough leverage to keep it off of him, keep its teeth from his neck. But the creature twisted and squirmed like quicksilver, his hand slipped a little and it dropped forward heavily, so he only managed to stop it inches from his throat.

For a second, Jack could only stare at himself, older but not by that much, it couldn't be that much, but another man all the same. Sheer instinct and several levels of training screamed at him to get the hell out of the room, the longer he was close to himself the greater the chances of a paradox. Another, slightly quieter part of his brain murmured questions - why would he ever have left the Doctor and Rose, what was he doing here in _Cardiff_, whys and hows and-

The time hound snarled, a sick, wheezing sound, and twisted free of the other Jack's grip to lunge at him again one last time, wicked jaws agape...

Rose shouted wordlessly, grabbed Jack's blaster from the holster at his waist, and fired. "I swear, Jack, if the batteries aren't working-"

A concussive blast knocked her back, and Jack moved on instinct to grab her, the momentum of the blast thumping them both onto the floor, Rose on top of Jack. She knocked the breath out of him, but he rolled over anyway to place himself on top of her, between her and the time hound, just in case...

And then he registered the sound he'd heard a second after the two of them hit the ground, a soft, wet _smack_... He slowly lifted his head to see the time hound in a twisted, broken heap at the base of the wall, unmoving, unbreathing, and the other Jack blinking first at the time hound and then at him in breathless surprise. Rose lifted her head too after a second, and stared.

"I've never seen it do that before," Rose said quietly after a moment.

The other Jack coughed, and pushed himself to his feet, rubbing at a lacerated shoulder like it was just sore, and not soaking his coat in blood. "Sonic cannon setting," he said, and then chuckled softly. "Haven't seen that one in ages. Thank you, by the way."

Rose grinned, shoving Jack off her and standing slowly herself. "Well, it wouldn't be the first time I've had to rescue you, Captain." Jack snorted, and smirked at her, and did his very best not to look his older self in the eyes.

From behind him, he heard Owen mutter, "Two Jacks. Just what I needed to end the day."

"Could be worse, Owen," Gwen said, though slowly. She was doing an admirable job of pretending to be less unsettled than she actually was. "It could be two of you."

* * *

Jack sent his team down to the hub, told Gwen and Owen not to speak to Tosh and Ianto about it, and wait in the boardroom for him so they could be debriefed. They went, with little argument, though Owen huffed a little and Gwen gave him the look that meant she was going to have a Talk with him at the earliest possible opportunity. He watched them walk away for a few seconds, down toward the door of the tourist information centre, and then sighed, turning back to face Rose and... himself.

"I guess this is goodbye, then." The words were out of his mouth before he realised how familiar they were, and only just held back a grimace. Familiar to him, maybe, but not to either of them, and they couldn't know how it ended...

Rose smiled at him, a quiet, sad smile that hurt more than encouraged, which probably wasn't the intention. Jack smiled back cheerfully anyway, like it didn't bother him that he hadn't seen her, not properly, for over a century, or that he'd read her name on a list of the dead not that long ago.

He didn't fail to notice the way his younger self stood a little too close to her, kept looking at her and then at anything but him. Jack could guess his thoughts well enough, though he couldn't remember. When would he lose her, when would he leave her, when would he become this stranger who stood in front of him, why and how and-

"I wish I could say we'd come back to see you," Rose said, "but-"

"Timelines," he said, that old familiar reason for everything he wanted and couldn't have. Rose nodded.

"Yeah."

Jack glanced past the two of them to the TARDIS, halfway across the Plass and practically shining, brilliant blue in the late afternoon sunlight. Some old, desperate, lonely part of him longed to run up to it, throw open the door and step inside and demand to know why he had been left, what had happened there on the Game Station, what the _hell_ had happened to him... But the Doctor wouldn't have any of those answers. Not yet. He looked back to Rose.

"Rose..." He smiled, and reached out to take her hand. "It's been... _wonderful_ to see you." Wonderful. Painful. They could almost be synonyms. He lifted her hand, kissed the back of it, smiling at her through it like this was the first time, standing on top of the Chula ship in front of Big Ben with the bombs all around.

The second he dropped her hand, Rose rolled her eyes, muttered, "Honestly, you can give me a proper goodbye," and reached up to pull him down to kiss her. It started off chaste, but did not remain so for long, and she tasted the same, smelled the same. He tangled his fingers in her hair at the nape of her neck, projecting in every way he could _I miss you, I loved you, I love you..._

They broke apart finally, Rose a little breathless, and she stared up at him for a second. "That was..." She broke off with a smile, glanced first to the younger Jack and then to the distant TARDIS before taking a step back. "We should go, before the Doctor starts to wonder where we got off to."

Jack took a step back himself, threw an arm up in a salute, and then watched as her lips flickered in another, sadder smile before she turned and walked away.

She didn't get far. A few metres away, she stopped, and turned back to frown at the other Jack, who hadn't moved. "Aren't you coming?"

"Give me- Give us a minute."

Rose watched him for a moment, brow furrowed in concern, but rather than arguing, she sighed and nodded, then started off again, only glancing over her shoulder once or twice. Jack raised an eyebrow at himself, waiting for the obvious question.

"What happened?" the younger man asked finally, meeting Jack's eyes. He could see fear there, wariness and uncertainty and the real question, _What will I become?_

"If you mean those two years, I _still_-"

"You _know_ what I mean."

Jack met his eyes for a few seconds more, then looked away. "Long story. Long time ago. And even if I tell you, it won't matter."

"_Why not_?" he growled. Jack would have worried that he was thinking about punching him, except that even that young, he wouldn't have been dumb enough to touch himself and risk a paradox.

"Because you won't remember." Jack reached into his pocket, pulled out two small doses of retcon, and held them out. After a moment, reluctantly, the younger man extended his hand, and Jack dropped the retcon into his palm, all without either of them touching each other. "One for each of you. she doesn't even have to know. Just... trust me."

The younger one snorted, lips quirking into a humorless smirk. Trust didn't come easily for people like him, especially when it came to his own memory. But then again, if he wasn't going to trust himself...

Jack let him search his face for a moment, blue eyes full of suspicion and inquiry, and had he _ever_ really looked that young, that scared, that hopeful and that alive? It didn't seem possible. He turned away, finally, without another word, and started to walk off, coat catching in the early evening breeze off the bay. He could see the questions in his eyes, but he wasn't going to answer any of them. He had two years of questions, and another century and change on top of that. He could live with one day more.


End file.
